The　purpose　of　this　paper　is　to　investigate　the　fatigue　properties　of　C17200　alloy　under　the　condition　of　quenching　aging　heat　treatment　at　high　temperatures,　and　to　provide　a　design　reference　for　its　application　in　a　certain　temperature　range.　For　this　purpose,　the　tensile　and　rotary　bending　fatigue　(RBF)　tests　were　carried　out　at　different　temperatures　(25　°C,　150　°C,　350　°C,　and　450　°C).　The　tensile　strength　was　obtained,　and　relationships　between　the　applied　bending　stress　levels　and　the　number　of　fatigue　fracture　cycles　were　fitted　to　the　stress-life　(S-N)　curves,　and　the　related　equations　were　determined.　The　fractured　surfaces　were　observed　and　analyzed　by　a　scanning　electron　microscopy　(SEM).　The　results　show　that　the　RBF　fatigue　performance　of　C17200　alloy　specimens　is　decreased　with　the　increase　in　test　temperature.　When　the　temperature　is　below　350　°C,　the　performance　degradation　amplitudes　of　mechanical　properties　and　RBF　fatigue　resistance　are　at　a　low　level.　However,　compared　to　the　RBF　fatigue　strength　of　1　×　107　cycles　at　25　°C,　it　is　decreased　by　38.4%　when　the　temperature　reaches　450　°C.　It　is　found　that　the　fatigue　failure　type　of　C17200　alloy　belongs　to　surface　defect　initiation.　Below　350　°C,　the　surface　roughness　of　the　fatigue　fracture　is　higher,　which　is　similar　to　the　brittle　fracture,　so　the　boundary　of　the　fracture　regions　is　not　obvious.　At　450　°C,　due　to　the　further　increase　in　temperature,　oxidation　occurs　on　the　fracture　surface,　and　the　boundary　of　typical　fatigue　zone　is　obvious.　©　2023　by　the　authors.